And they have told the Goodison club that they must meet the figure in one payment, and make it straight away.

Martinez was hoping to land Batshuayi as Hull target Nikica Jelavic ’s potential replacement and pay the fee in instalments, but Standard - who sold Marouane Fellaini to Everton in 2009 - will stick to the letter of the contract.

While Standard want Batshuayi to stay for the rest of the season, the player fancies the move - and there have been talks.

Martinez had to pay the trigger figure in full for Arouna Kone when he signed him for Wigan from Spain's Levante in 2012, and will have to do the same again.